1. Field of the Invention
The present invention relates generally to a system and method of transmitting television broadcast signals, in particular, to a system and method of dynamically detecting damage to video signals caused by external interference, or sporadic nulls, and repairing damaged video signals.
2. Description of the Background Art
Wireless communications devices are proliferating at a rapid pace in recent years. For example, in the area of personal area network (PAN), it becomes increasingly desirable to use cable-free connections for data exchange or communication between devices such as desktop computers, mobile computers, handheld devices, mobile phones, digital cameras, and printers.
For example, an increasing number of wireless devices are now developed using Bluetooth™ technology for wireless communications. Bluetooth, commonly known as a wireless PAN technology for short range delivery of digital data or voice, transmits signals in unlicensed 2.4 GHz band and uses frequency hopping spread-spectrum (“FHSS”) technique that changes its frequency 1600 times per second. HomeRF™ (Home Radio Frequency), another PAN technology, also operating on the 2.4 GHz range, changes 50 times per second to transmit digital voice and data between mobile devices and desktop devices within a range of 150 feet. These emerging technologies eliminate the need of numerous and inconvenient cable connections between electronic devices.
However, one of the problems associated with these growing wireless communications technologies is the interference they may cause to other wireless transmissions that are carried within the same or overlapping frequency range. In particular, in an FHSS environment using Bluetooth and other wireless technologies using the frequency hopping technique, certain types of wireless data or voice transmissions are vulnerable to such interference.
For example, when a digital camera captures live motion video or still images and transmits the video signals wirelessly to a host computer using the same 2.4 GHz band and a raster-based system, e.g., NTSC (National TV Standards Committee) or PAL (Phase Alternating Line) compatible system, the loss of data due to the interference from Bluetooth or other wireless FHSS devices causes artifacts and flickers in the video images. As the number of the external Bluetooth transmissions increases, the interference becomes even worse and significantly deteriorates the quality of the video.
Therefore, it is desirable to have a system and method of effectively detecting the outside interference caused by Bluetooth or other radio frequency transmissions, and repairing the corrupted data. In particular, in broadcasting video signals, the desired method and system is capable of dynamically detecting the affected video signals and correcting the corrupted data for real time video or still images to improve the overall quality of the video images.